Previous data from our laboratory showed that CD3 membrane expression was downmodulated after experimental infection of CD4+ T cells with HIV-1 [14-17], HIV-2[18], as well as in patients with CD3- CD4+ T-cell lymphoma mediated hypereosinophilic syndrome [19], all linked to a specific defect in CD3γ gene transcripts. The gene discussed is CD4; the disease is hypereosinophilic syndrome.